Manufacture of lube oil containing overbased sulfurized calcium alkylphenolate

ABSTRACT

METHOD OF PREPARING A LUBRICATING OIL COMPOSITION CONTAINING A PARTIALLY HYDROLYZED OVERBASED SULFURIZED CALCIUM ALKYLPHENOLATE DETERGENT OF ANTIOXIDANT AND SKIN FORMING RESISTANT PROPERTIES AND OF REDUCED VISCOSITY AND IMPROVED FLTERABILITY COMPROSING FIRST CONTACTING A SULFURIZED NORMAL CALCIUM ALKYLPHENOLATE WITH A CALCIUM ALKOXYALKOXIDE WHILE SIMULTANEOUSLY BLOWING THE REACTION MIXTURE WITH NITROGEN GAS AT A RATE OF BETWEEN ABOUT 0.25 AND 0.6 S.C.F.H/GALLON OF REACTION MIXTURE, SUBSEQUENTLY STRIPPING THE REACTION MIXTURE WITH SAID GAS AT A RATE OF BETWEEN ABOUT 0.25 AND 0.6 S.C.F.H./GALLON OF RESULTANT MIXTURE AND THEN SECOND CONTACTING THE STRIPPED MIXTURE WITH WATER WHILE SIMULTANEOUSLY BLOWING DURING SAID SECOND CONTACTING THE STRIPPED MIXTURE WITH SAID GAS AT A RATE OF BETWEEN ABOUT 0.1 AND 0.2 S.C.F.H./GALLON OF STRIPPED MIXTURE.

United States Patent O 3,706,632 MANUFACTURE OF LUBE 01L CONTAININGOVERBASED SULFURIZED CALCIUM ALKYL- PHENOLATE Frederic F. Day and GeorgeE. Emery, Port Arthur, Tex., and James G. Dadura, Fishkill, N.Y.,assignors to Texaco Inc., New York, NY. No Drawing. Filed Oct. 19, 1970,Ser. No. 82,190 Int. Cl. C10m 1/38, 1/54 U.S. Cl. 25242.7 5 ClaimsABSTRACT OF THE DISCLOSURE Method of preparing a lubricating oilcomposition containing a partially hydrolyzed overbased sulfurizedcalcium alkylphenolate detergent of antioxidant and skin formingresistant properties and of reduced viscosity and improved filterabilitycomprising first contacting a sulfurized normal calcium alkylphenolatewith a calcium alkoxyalkoxide while simultaneously blowing the reactionmixture with nitrogen gas at a rate of between about 0.25 and 0.6s.c.f.h./gallon of reaction mixture, subsequently stripping the reactionmixture with said gas at a rate of between about 0.25 and 0.6s.c.f.h./gallon of resultant mixture and then second contacting thestripped mixture with water while simultaneously blowing during saidsecond contacting the stripped mixture with said gas at a rate ofbetween about 0.1 and 0.2 s.c.f.h./gallon of stripped mixture.

BACKGROUND OF THE INVENTION It is well known that lubricating oils tendto deteriorate under the conditions of use in present day diesel andautomotive engines with attendant formations of sludge, lacquer andresinous materials which adhere to the engine parts, particularly theengine rings, grooves and skirt, thereby lowering the operatingefiiciency of the engine. To counteract the formation of these deposits,certain chemical additives have been found which when added tolubricating oils have the ability to keep the deposit forming materialssuspended in oil so the engine is kept clean and in efiicient operatingcondition for extended periods of time. These agents are known in theart as detergents or dispersants. Metal organic compounds areparticularly useful in this respect. These metal organic compounds areconsidered to be effective because they provide alkalinity to neutralizestrong organic and inorganic acids and are capable of dispersingdeposits and deposit precursors into the oil phase. Overbased sulfurizedmetal alkylphenolates have been found to be particularly effectivedispersants in lubricating oils.

Hereinbefore and hereinafter, by the term overbased it is meant that theratio of the number of equivalents of calcium moiety to the number ofequivalents of phenol moiety is greater than 1, that is, the calciummetal ratio is greater than 1. In contrast, the equivalent ratio ofcalcium to phenol moiety in normal sulfurized calcium alkylphenolate isabout 1:1, i.e., a calcium metal ratio of 1.

U.S. Pat. No. 3,474,035 describes a lubricating composition comprising ahydrocarbon oil of lubricating viscosity containing between about 0.1and 90 wt. percent of a high temperature alkaline dispersant consistingof a novel partially hydrolyzed overbased sulfurized calciumalkylphenolate having antioxidant and resistant skin formationproperties and which is not required to be in the carbonated form inorder to promote a high degree of overbasing. Further, the proceduretherefor is also set forth. Although the product of the patent is asuperior lube oil additive, problems arose in its manufacture on a largescale (tons) commercial basis. Specifically, the patents procedurefrequently produced a product of somewhat higher viscosity than desiredfor the particular run thus requiring cutting back the product with alow viscosity oil. Further, the filterability and solubility of theproduct was frequently less than satisfactory. Therefore, there was aneed to produce a product of the type set forth in U.S. 3,474,035 but ofa reduced viscosity and improved filterability and solubility.

SUMMARY OF INVENTION We have discovered and this constitutes ourinvention, a method of preparing a lubricating oil concentrate ofpartially hydrolyzed overbased sulfurized calcium alkylphenolate asdescribed in U.S. 3,474,035 of reduced viscosity and improvedfilterability. More specifically, our method broadly comprises firstcontacting in hydrocarbon lube oil medium a sulfurized normal calciumalkylphenolate with a calcium alkoxyalkoxide while simultaneouslyblowing the reaction mixture with nitrogen gas at a rate of betweenabout 0.25 and 0.6 s.c.f.h./gallon to form overbased sulfurized calciumalkylphenolate, stripping the overbased sulfurized calciumalkylphenolate reaction mixture with nitrogen gas at a rate of betweenabout 0.25 and 0.6 s.c.f.h./gallon overbased mixture, subsequentlycontacting said stripped overbased calcium alkylphenolate with waterwhile simultaneously blowing the resultant reaction mixture with saidgas at a rate of between about 0.1 and 0.2 s.c.f.h./gallon of strippedmixture and recovering a lube oil concentrate of hydrolyzed sulfurizedcalcium alkylphenolate from the reaction mixture. A material aspect ofthe invention is the discovery that in order to obtain a product ofreduced viscosity, nitrogen gas introduction is essential duringoverbasing, stripping and hydrolysis, and further, the introduction mustbe with in the prescribed gas rates. Operation outside said ratesresults in products'of substantially and undesirably increasedviscosity.

DETAILED DESCRIPTION OF THE INVENTION Specifically, the lubricantcomposition of the method of the invention comprises first contacting inthe presence of a lubricating oil, a sulfurized normal calciumalkylphenolate having a sulfur content between about 0.1 and 10 wt.percent which is characterized by the theoretical formula:

( -l-y/ Ca In the above formula R is a monovalent saturated aliphatichydrocarbon radical (alkyl) of from 4 to 100 carbons, x is an averageinteger of from 1 to 4 and y is an average integer from to 10. It is tobe noted x and y are defined as average integers since sulfurized normalcalcium alkylphenolate is in essence a complex mixture of monosulfideand polysulfide or a mixture of polysulfides as theoretically defined.In any case, the R group is mainly in the para position with the sulfurmainly in the ortho position. Further, there is probably also asignificant amount of covalent character to the calcium-oxygen bond.

The first contacting is conducted at a temperature between about 10 and200 0., preferably between about 150 and 200 C. for a period of time,e.g., 0.001 to 10 or more hours, preferably between about 1 and hours,utilizing a mole ratio of normal sulfurized calcium alkylphenolate toalkoxide reactant between about 1:01 and 1:25, preferably between about1:1 and 1:2.

The lubricating oil medium, advantageously constitutes between about and90 wt. percent of the first reaction mixture, preferably between about30 and 70 wt. percent, resulting in final lubricating oil concentrateproduct containing an overbased calcium concentrate of between about 10and 90 wt. percent, preferably between about 30 and 70 wt. percent.

The nitrogen flow is introduced directly into the reaction mixtureliquid, preferably by introducing into the bottom area of the reactorand passing through the liquid in upward flow and continually removingsaid gas from the upper region of the reactor system. Normally, thenitrogen exerts a positive pressure in the reactor system of betweenabout 1 and 4 p.s.i.g.

Following said first contacting, the resultant mixture is stripped bycontinuing said nitrogen flow at a rate between about 0.25 and 0.6s.c.f.h./gallon at a temperature between about 150 and 200 C. andpermitting the volatile materials to be removed. The stripped firstreaction mixture is then second contacted with water for a period oftime, e.g., between about 0.1 and 10 hours, preferably between about 2and 4 hours, at a temperature between about 10 and 250 C., preferablybetween about 150 and 200 C. utilizing a mole ratio of water to calciumalkoxide reactant of between about 100:1 and 0.211 while simultaneouslyblowing the reaction mixture with nitrogen gas at a rate of betweenabout 0.1 and 0.2 s.c.f.h./ gallon, preferably between about 0.15 and0.16 s.c.f.h./ gallon. The Water in the contacting may be either in itsliquid or vapor form or mixtures thereof, and the contacting with wateris continued until the overbased sulfurized calcium alkylphenolate isbetween about and 70% hydrolyzed.

The water introduction into the liquid reaction mixture is preferablyintroduced at the bottom of the reactor as steam and passedtherethrough. At the completion of the hydrolysis step the residualunreacted water is desirably substantially removed from the finalreaction mixture, e.g., by stripping with nitrogen gas, e.g., at atemperature between about 150 and 200 C. and at a rate of between about0.25 and 0.60 s.c.f.h./gallon. The term at least a substantial removalof water is intended to denote removal of water to the extent that lessthan about 1 wt. percent water exists in the final reaction mixture.

The crude product may be further purified by standard means such asdistilling any diluent and by-product such as alkoxyalkanol which is notremoved during the excess water removal step and filtering the residuethrough a standard pressure filter plate at about 20 to 200 C. underbetween about 0.1 to 100 p.s.i. pressure utilizing a diatomaceous earthfilter aid.

It is to be noted the extent of hydrolysis is dependent on time,temperature and reactant ratios, therefore, periodic sampling andanalysis of the overhead and/or reaction mixture is necessary todetermine the extent of hydrolysis. As a practical matter once theamount of hy- 4 drolysis is decided upon, the particular set ofconditions to produce the desired degree of hydrolysis for a givenreactor can be determined. After such a determination the need forperiodic sampling becomes unnecessary.

In the foregoing procedure, it is theorized the calcium alkoxyalkoxidecomplexes with, or is dispersed by, the sulfurized normal calciumalkylphenolate and the water hydrolyzes a portion of the complex calciumalkoxyalkoxide moiety with about 50% hydrolysis of said moiety beingoptimum in respect to stability of the product at high metal ratios.

The following theoretical equations further describe the preparation ofthe hydrolyzed overbased sulfurized calcium alkylpheuolate component ofthe compositions of the invention. It is to be noted Q below istheorized as sulfurized normal calcium alkylpheuolate as heretoforedefined.

In the foregoing equations R' and A are as heretofore defined, n is anaverage integer from about 0.2 to 1.4 and m is an average integer from0.1 to 2.5. Under preferred circumstances It is an average integerbetween about 0.8 and 1.2.

In the foregoing procedure as herefore stated a material aspect inrespect to obtaining a product of reduced viscosity is the rate ofblowing with inert gas during overbasing, stripping of the overbasedmixture and during hydrolysis. Rates employed outside these rangesresult in a product of substantially increased viscosity. In regard tothe unexpected importance of the use of nitrogen and the rate ofintroduction thereof, it is theorized that the nitrogen gas coupled withits rate of introduction has a direct effect on particle size of theformed hydrolyzed overbased sulfurized calcium alkylpheuolate. Oneexplanation is a rate higher than the maximum allowed produces particlesso fine that they are inadequately coated and they agglomerate resultingin a too viscous product of reduced filterability and also a productwhich has poor solubility even upon filtration and oil dilution. It isfurther theorized when the nitrogen gas rate is below the minimum setforth, particles are formed that are so large as to also result in a tooviscous product and also a product having poor solubility even upon oildilution. To summarize, we have unexpectedly discovered that thenitrogen gas introduction during overbasing, stripping and hydrolysisaffects particle size which in turn affects viscosity, filterability andsolubility of the final product. To obtain minimum viscosity and maximumfilterability and solubility, a particular set of conditions,ingredients and amounts coupled with a defined rate range of nitrogengas blowing in the overbasing, stripping and hydrolysis phases arerequired.

The nitrogen gas employed preferably has an impurity content (oxygen andcarbon dioxide) of less than about 0.5 wt. percent. Impurities such ascarbon dioxide and oxygen undesirably degrade the calcium alkoxyalkoxidereactant.

In a preferred embodiment the sulfurized normal calcium alkylpheuolatereactant is prepared in the following manner:

The first stage comprises contacting, preferably in a hydrocarbonlubricating oil medium advantageously constituting between about 15 and70 wt. percent of the final reaction mixture, an alkylphenol of theformula:

where R is as heretofore defined with a calcium alkoxyalkoxide of theformula:

where A and R are as heretofore defined, at a temperature between aboutand 150 C., utilizing a mole ratio of alkylphenol to calciumalkoxyalkoxide of about 2 to form a normal calcium alkylphenolatecharacterized by the formula:

Prior to the next stage of the reaction the alkoxyalkanol solvent (ifused) and by-product is preferably removed from the reaction mixture bystandard means such as stripping with an inert gas (e.g., nitrogen) atthe temperature of distillation for said alcohol. The purpose of thestripping is to prevent sulfur contamination of the alkoxyalkanolby-product which unless removed would take place in the next stage.

To the stripped or unstripped reaction mixture in the first stage thereis charged at a temperature between about 75 and 250 C., sulfur in amole ratio of sulfur to normal calcium alkylphenolate of between about0.15:1 and 8:1, preferably between about 0.5 :1 and 3:1. The sulfur isdesirably introduced as a slurry in mineral oil in between about 10 andwt. percent concentration. At the end of the sulfur charge thetemperature is maintained for a period of time, e.g., between about 1and 25 hours, preferably under gas stripping conditions to removevolatile sulfur by-products. The resultant product is sulfurized normalcalcium alkylphenolate having a sulfur content between about 0.1 and 10wt. percent and a calcium metal ratio of about 1.

Under preferred conditions, stripping of the normal sulfurized calciumalkylphenolate with carbon dioxide which is bracketed by nitrogen gasstripping is most desirable since carbon dioxide facilitates removal ofvolatile, odorous, sulfurous by-products. In addition, the carbondioxide deodorization treatment of the sulfurized normal calciumalkylphenolate appears to somewhat improve the filterability andstability of the final hydrolyzed overbased product. The inert and 00stripping rate generally employed is between about 0.1 and 10 s.c.f.h./gallon of reaction mixture at between about 10 and 250 C.

Alternative means for manufacture of the sulfurized normal calciumalkylphenolate reactant contemplated herein call for reactingalkylphenol with sulfur dichloride with continuous removal ofhydrochloric acid by-products and reacting the resultant alkylphenolsulfide with calcium oxide to form a normal sulfurized calciumalkylphenolate as heretofore defined. This alternative procedurealthough producing the desired product has the undesirable feature ofproducing hydrochloric acid by-products which require relatively costlyapparatus and handling techniques for removal, and also generallyresults in the incomplete neutralization of the phenol.

Another alternative procedure for forming the sulfurized normal calciumalkylphenolate reactant is contacting an alkylphenol with calcium oxideor calcium hydroxide in the presence of a glycol such as ethylene glycolto form the calcium alkylphenolate with simultaneous sulfurization. Theprocess has the disadvantage of usually requiring reduced pressure toremove the solvent glycol, thus increasing equipment requirements. Also,the normal sulfurized calcium alkylphenolate prepared in this wayretains residual glycol decomposition products which tend to degrade thehigh temperature dispersant properties of the product.

In a still further preferred embodiment the calcium alkoxyalkoxidereactant as heretofore defined utilized in the preparation of thesulfurized normal calcium alkylphenolate reactant and overbased productis prepared by contacting an alkoxyalkanol of the formula where R and Aare as heretofore defined with calcium carbide preferably in thepresence of a filter aid such as diatomaceous earth utilizing a moleratio of alcohol to calcium carbide of between about 5:1 and 8:1 andfilter aid when employed of between about 0.5 and 2.0 wt. percent of thereaction mixture. The presence of filter aid facilitates thepurification of the product via filtration, the product being recoveredas the purified filtrate. The reaction is conducted at a temperaturebetween about 60 and 130 C., and the product is isolated as heretoforedescribed via filtration to remove insolubles and purging to remove theacetylene by-product.

In all stages of the manufacturing procedure the reaction ingredientsare preferably stirred.

The content of the aforedescribed hydrolyzed overbased sulfurizedcalcium alkylphenolate in the lubricating composition of this inventionmay range anywhere from 0.1 to wt. percent. The higher concentration,e.g., between about 30 and 90 wt. percent are normally found incompositions directly from the manufacture of the hydrolyzed overbasedcalcium alkylphenolate whereas the preferred concentration in finallubricating oil compositions of the hydrolyzed overbased phenolateadditive for automotive use is between about 0.1 and 5 wt. percent. Inany event in the entire range, the additive in the lubricating oilcomposition will function as an alkaline dispersant.

In the finished lubricating oil compositions other additives may beincluded. These other additives may be any of the standard suitable pourdepressants, heat thickening sulfurized fatty oils, additional sludgedispersants (e.g., petroleum sulfonates), antioxidants, silver corrosioninhibitors, viscosity index improvers and oiliness agents. Exactly whatadditional additives are included in the finished oils and theparticular amounts will, of course, depend on the particular use andconditions desired for the finished oil product.

Suitable base oils useful in the compositions of the invention as wellas diluent in the manufacture of the hydrolyzed overbased sulfurizedcalcium alkylphenolate component include a wide variety of hydrocarbonlubricating oils such as naphthenic base, paraflinic base and mixed basemineral oils or other hydrocarbon lubricants, e.g., lubricating oilsderived from coal products and synthetic oils, e.g., alkylene polymerssuch as polypropylene and polyisobutylene of a molecular weight betweenabout 250 and 2500. Advantageously, lubricating oils having an SUSviscosity at F. between about 50 and 2000 are employed.

Examples of the alkylphenol reactants contemplated herein are4-octylphenol, 4-tertiary octylphenol, Z-decylphenol, 2-dodecylphenol,4-hexadecylphenol, 2,4-didodecylphenyl, 2-nonylphenol,4-tricontylphenol, 4-eicosylphenol, a mixture of a decylphenol anddodecylphenol (C -C alkylphenol) and mixtures of 2 and 4 positionedmonoalkyl and dialkylphenol. It is to be noted the alkylphenol employedwill normally have the alkyl groups in the para position. However,2,4-substituted dialkylphenols may also be employed. The onlyrestriction is one ortho or para position of the alkylphenol reactant isdesirably available for sulfurization.

Examples of the calcium alkoxyalkoxide reactants contemplated herein arecalcium 2-methoxyethoxide, calcium l-methoxypropoxide, calcium3-methoxybutoxide, calcium ethoxy-Z-ethoxide and calcium4-dodecoxyhexoxide. In order to facilitate reactant contact, the calciumalkoxyalkoxide reactant is preferably employed in conjunction withvolatile solvent such as the corresponding alkoxyalkanols,2-methoxyethanol, l-methoxypropanol, 3-methoxybutanol etc. The calciumalkoxyalkoxide reactant concentration in the solvent solution isnormally between about 20 and 60 wt. percent although higher and loweramounts may be employed. The calcium alkoxyalkoxide reactant is preparedby standard means such as reacting calcium metal, calcium hydride orcalcium carbide with the corresponding alkoxyalkanol desirably at atemperature between about and 150 C. Of the inorganic calcium reactants,calcium carbide is preferred for economic reasons.

Examples of the sulfurized normal calcium alkylphenolate reactants basedon the theoretical formula:

are where R is 4-octyl, x is 1 and y is 0; R is 4-dodecyl, x is 1 and yis 1; R is 4-eicosyl, x is 3 and y is R is 2,4-didecyl, x is 2 and y is3; and mixtures thereof. It is to be noted x and y are defined asaverage integers.

The following examples further illustrate the method of the inventionbut are not to be construed as limitations thereof.

EXAMPLE I This example illustrates the preferred preparation of calciumalkoxide reactant.

To a 3,000 gallon reactor fitted with a variable speed stirrer and meansfor heating, collecting volatile overhead, and purging with gases, therewere charged at ambient temperature (72 F.) 18,000 lbs. ofZ-methoxyethanol, 3,000 lbs. calcium carbide and 250 lbs. diatomaceousearth, and the reactor was purged with nitrogen to produce a nitrogenatmosphere. The reaction mixture was heated with stirring to 60 C.whereupon the temperature rose to about 100 C. due to the heat ofreaction. After about one hour, the mixture was heated to about 120 C.for a period of 4 hours with high speed mixing and nitrogen purging.While continuing to mix at high speed the product is pumped by means ofa centrifugal slurry pump through a plate and frame type filter and backto the reactor. When the bulk of the solids have been transferred to thefilter, the filtrate is diverted to storage as a clear solution ofcalcium Z-methoxyethoxide in Z-methoxyethanol.

EXAMPLE II This example illustrates the preparation of the lube oilconcentrate of the sulfurized normal calcium alkylphenolate reactant.

To a 3,000 gallon stainless steel reactor fitted with a variable speedstirrer and means for heating, collecting volatile overhead, purgingwith gases, introduction of reactants and removal of product, there wascharged 1,042 gallons of a parafi'inic oil having an SUS viscosity ofabout 100 at 100 F. and 472 gallons of C -C alkylphenol. Stirring andnitrogen blowing through a sparger placed in the bottom of the reactorat a rate of 250 s.c.f.h./ gallon were initiated and the reactorcontents were heated to a temperature of about 165 C. With continuedheating and stirring at this temperature, 372 gallons of 36 Wt. percentcalcium 2-methoxyethoxide in 2-methoxyethanol were added at a rate of4.5 gallons/minute and upon completion the nitrogen rate was increasedto 900 s.c.f.h. The temperature was then increased to about 175 C. for a3 'hour period and removing during said period excess 2-methoxyethanol.At the end of the 3 /2 hour period the nitrogen rate was reduced to 500s.c.f.h. and a slurry of 495 lbs. of sulfur in 208 gallons of paraffiniclubricating oil of an SUS viscosity of about 100 at 100 F. wasintroduced into the reactor system and the temperature of about 175 C.and nitrogen blowing at 500 s.c.f.h. was continued for a period of 5.5hours. At the end of the 5.5 hour period nitrogen blowing was ceased andthe mixture was blown with carbon dioxide at a rate of 1000 s.c.f.h. fora period of 1 hour while maintaining the 175 C. temperature and at theend of the 1 hour period nitrogen blowing was resumed with the ceasingof carbon dioxide blowing for an additional 1 hour period to strip outexcess C0 The resultant product was analyzed and determined to besulfurized normal calcium alkylphenolate lube oil concentrate of thefollowing analysis:

TABLE I Test: Results Calcium, wt. percent 2.0 Sulfur, wt. percent 2.0TBN (HClO titration) 56 Specific gravity, 60/60 0.96 Viscosity, SUS at210 F Flash point, F. 360 Sulfated ash, wt. percent 6.8

The product was determined to be a lubricating oil solution containing32 wt. percent sulfurized normal calcium 4-C -C alkylphenolate having ametal ratio of about 1.

EXAMPLE III This example illustrates the preparation of the lube oilconcentrate of overbased sulfurized calcium alkylphenolate of reducedviscosity and further illustrates the criticality of inert gas rate inrespect to obtaining a product of reduced viscosity.

The apparatus and sulfurized normal calcium alkylphenolate productdescribed in Example II were utilized.

To 12,900 lbs. of oil concentratecontaining about 32 wt. percentsulfurized normal calcium alkylphenolate produced in Example IImaintained at a temperature of about 175 C. there was charged 1 pint ofsilicone polymer (1,000,000 M.W.) antifoamant and 744 gallons of 36 wt.percent calcium-Z-methoxyethoxide in Z-methoxyethanol produced inExample I at a rate of 4.5 gallons/minute while nitrogen blowing thereaction mixture at a rate of 900 s.c.f.h. (within the 0.250.6s.c.f.h./gallon range). This overbasing step was followed by a 3-hourstripping period to strip out excess 2-methoxyethanol maintainingnitrogen rate at 900 s.c.f.h. (within the 0.250.6 s.c.f.h./ gallonrange). At the end of this first stripping step and still maintainingthe temperature at 175 C., lbs./ hour of steam was introduced into thereaction mixture at 175 C. for a period of 2.25 hours for a total amountof 225 lbs. introduction of water (as steam) while continuing to blow ata decreased rate of 250 s.c.f.h. (within 0.1-0.2 s.c.f.h./gallon range)with nitrogen during this hydrolysis step. At the end of the hydrolysisperiod nitrogen blowing was increased to a rate of 900 s.c.f.h. (within0.25-0.6 s.c.f.h./gallon range) for a period of 6 hours to stripvolatile materials therefrom. At the end of the second stripping therewas introduced into the reaction mixture lbs. of diatomaceous silica andthe resultant mixture was passed through a precoated filter ofdiatomaceous earth at about 150 C. at a nominal pressure of about 100p.s.i.g. The resultant product was then analyzed and determined to be alube oil concentrate of overbased sulfurized calcium 4-C -Calkylphenolate which is about 50% hydrolyzed. Eight runs Were made. RunsA, B, C, D, E and F represent the procedure of the invention. Runs G andH are comparative runs, wherein the nitrogen rates are outside the rangecontemplated herein. A comparison of the representative runs with thecomparative runs demonstrate that the representative runs have asubstantially lower viscosity than the comparative runs. The test dataand results are reported below in Tables II-A and II-B.

TABLE II-A Run A B C Nitrogen rates s.c.f.h.:

Overbasing 900 900 900 Stri ping- 900 900 900 Hy olysis 250 250 250Tests on finished products:

Specific gravity 60/60. 0. 9778 Flash COO, F 365 Viscosity SUS at 210 F215 Total base No. (TBN)- 147 Calcium, wt. percent. 9 5. 4 5. 3 Sulfur,wt. percent 2. 1. 7 1.8 Sediment, vol. percent. 0. 04 0. 01 0. 04 00 wt.percent 0. 6 0. 11 0. 06 Lumetron, 6 hrs. after blending:

vol. percent in oil X 3. 5 5. 0 2. 5 5 vol. percent in oil Y 4. 5 8.0 5.0

See footnotes at end of Table II-C.

TABLE II-B Run D E F Nitrogen rate s.c.t'.h.:

Overbasing. 900 900 900 Stripping... 900 900 900 Hydrolysis 250 250 250Tests on finished product Specific gravity, 60/60--- 0.9722 0. 970 0.972 Flash COC, F 350 370 360 Viscosity SUS at 210 F 209 222 200 Totalbase No. (TBN) 151 134 136 Calcium, wt. percent-.- 5.4 4. 8 4. 8 Sulfurwt. percent.. 1. 6 1. 9 1. 6 Sediment, vol percen 0.01 0.01 0.02 00 wt.percent- 0. 20 0. 25 0. 41

Lmnetron, 6 hrs. alter blending:

5 vol. percent in oil X 2. 5 2. 5 5. 0 5 vol. percent in oil Y 7. 0 3. 516. 0

See footnotes at end of Table 11-0.

TABLE IIC Run G G 1 e H d en rates s.c.i.h.:

gierbasing 250 250 1, 000 Stripping 250 250 1, 000 Hydrolysi 0 0 250Tests on finished product Specific gravity 60/60. 0. 0677 Flash 000 37 FViscosity SUS at 210 F.- Total base No. (TBN) Calcium, wt. percentSuliur, wt. percent Sediment, vol. percent.

5 vol. percent in oil X 5 vol. percent in oil Y 5 Oil X is a mineral oilof 130 SUS viscosity at 100 F.

b Oil Y is a. mineral oil of 340 SUS viscosity at 100 F.

0 Run G product diluted with 12 vol. percent of a mineral oil of an SUSviscosity of 100 at 100 F.

d Final product diluted with 20 vol. percent of a mineral oil of an SUSviscosity of 100 at 100 F.

We claim:

1. A method of preparing a hydrolyzed overbased sulfurized calciumalkylphenolate hydrocarbon lubricating oil composition comprising firstcontacting in a hydrocarbon lubricating oil medium a sulfurized normalcalcium alkylphenolate having a sulfur content of between about 0.1 andwt. percent and a calcium metal ratio of about 1 wherein said alkylgroup is from 4 to 100 carbons with calcium alkoxyalkoxide of theformula:

where A is alkanediyl of 1 to 6 carbons and R is alkyl of 1 to 25carbons, at a temperature between about 10 and 200 C. whilesimultaneously introducing into the reaction mixture during said firstcontacting nitrogen gas at a rate of between about 0.25 and 0.6s.c.f.h./gallon utilizing a mole ratio of calcium alkoxyalkoxide to saidsulfurized normal alkylphenolate of between about 0.121 and 25:1, saidhydrocarbon oil being present in said first contacting in an amount ofbetween about 10 and 90 wt. percent, stripping the resultant reactionmixture with nitrogen gas at a gas rate of between about 0.25 and 0.6s.c.f.h./ gallon resultant mixture and at a temperature between about 10and 200 C., subsequently second contacting said overbased sulfurizedcalcium alkylphenolate with water at a temperature between about 10 and250 C. while simul- .taneously introducing into said stripped mixturenitrogen gas at between about 0.1 and 0.2 s.c.f.h./gallon strippedmixture utilizing a mole ratio of water to calcium alkoxyalkoxide ofbetween about 100:1 and 02:1, said water contacting continuing untilbetween 20 to 70 wt. percent of said overbased sulfurized calciumalkylphenolate is hydrolyzed, subsequently removing residual water andrecovering said hydrocarbon oil composition, said nitrogen gas beingcontinually introduced during said first contacting, said stripping andsaid second contacting.

2. A method in accordance with claim 1 wherein said sulfurized normalcalcium alkylphenolate is sulfurized normal calcium 4-C -Calkylphenolate and said calcium alkoxyalkanol is calcium2-methoxyethoxide.

3. A method of producing a hydrocarbon lubricating oil compositioncontaining between about 0.1 and wt. percent of between about 20 and 70wt. percent hydrolyzed overbased sulfurized calcium alkylphenolatehaving a calcium metal ratio of between about 1.1 and 3.5 comprising:

(a) first contacting in a lubricating oil medium an alkylphenol of theformula:

where R is an alkyl of from 4 to carbons with a calcium alkoxyalkoxideof the formula where A is a divalent saturated aliphatic hydrocarbon offrom 1 to 6 carbons and R is alkyl of from 1 to 25 carbons in thepresence of a hydrocarbon lubricating oil of an SUS viscosity betweenabout 50 and 2000 at 100 F. utilizing a mole ratio of said alkyl-.phenol to said calcium alkoxyalkoxide of about 2:1 at a temperaturebetween about 10 and 250 C. to form a first reaction mixture containingthe lube oil concentrate of the corresponding calcium alkylphenolate,

(b) subsequently contacting said formed calcium alklyphenolate withsulfur in a mole ratio of sulfur to said alkylphenol of between about0.15:1 and 8:1 at a temperature between about 75 and 250 C. to form asecond reaction mixture containing sulfurized normal calciumalkylphenolate having a sulfur content of between about 0.1 and 10 wt.percent in a lube oil concentrate,

(c) contacting said lube oil solution of said sulfurized normal calciumalkylphenolate with an additional amount of said calcium alkoxyalkoxidewhile blowing during said contacting the resultant reaction mixture withnitrogen gas at a rate of between about 0.25 and 0.6 s.c.f.m./gallonsaid lube oil solution at a temperature between about 10 and 200 C. in amole ratio of said sulfurized normal calcium alkylphenolate to saidadditional calcium alkoxyalkoxide of between about 1:0.1 and 1:25 and toform a third reaction mixture containing an overbased sulfurized calciumalkylphenolate having calcium metal ratio of between about 1.1 and 3.5,

(d) stripping the resultant reaction mixture with nitrogen gas at a gasrate of between about 0.25 and 0.6 s.c.f.h./ gallon resultant mixture ata temperature of between about 10 and 250 C. to form a fourth reactionmixture,

(e) subsequently contacting the stripped mixture with water whilesimultaneously blowing the stripped mixture during said contacting withnitrogen gas at a rate of between about 0.1 and 0.2 s.c.f.h./gallonstripped mixture at a temperature between about 10 and 250 C. in a moleratio of said water to said additional calcium alkoxyalkoxide of betweenabout 100:1 and 0.2:1 until 20 and 70 wt. percent said overbasedsulfurized calcium alkylphenolate is hydrolyzed,

(f) then substantially removing residual water by stripping the finalreaction mixture of step (e) with nitrogen gas at a nitrogen gas rate ofbetween about 0.25 and 0.60 s.c.f.h./gallon,

said nitrogen gas being continually introduced during all phases of saidsteps (0), (d), (e) and (f).

4. A method in accordance with claim 3 wherein the resultant reactionmixture of steps (a), (b) and (f) are stripped with inert gas betweenabout 100 and 250 C. wherein the resultant reaction mixture followingsaid contacting with sulfur is stripped with carbon dioxide, and

wherein the residue of step (t) is filtered and said composition isrecovered as filtrate.

5. A method in accordance with claim 4 wherein said alkylphenol is 4-C-C alkylphenol and said calcium a1- koxyalkoxide is calciumZ-methoxyethoxide.

References Cited DANIEL E. WYMAN, Primary Examiner W. H. CANNON,Assistant Examiner US. Cl. X.R.

